1. Field of the Invention
This invention relates generally to disposable beverage container lids and more particularly thin, thermoplastic polymeric lids of the type conventionally employed as temporary closures for food and beverage containers wherein such lid includes a flap or tear strip which may be folded back to allow drinking access from the container without removing the entire lid.
2. Brief Description of the Prior Art
The typical cup or beverage container lid is generally comprised of a thin, resilient polymeric material which includes a relatively flat central portion which nests within and below the rim of the cup or container and a rim-engaging means that is adapted to engage the container rim in a releasable manner. Conventionally, drinking access is achieved by either removing the lid from the container or by providing the lid with an access flap or tear strip. Such access flap or tear strip is usually provided through the use of tear impressions which begin on the central portion of the lid in relatively close proximity to one another and extend outward to or through the point where the lid engages the cup rim.
U.S. Pat. No. 4,322,015 to Bailey teaches a cup lid of the type described above which further includes at least one molded-in protrusion extending up from the central portion of the container lid adapted to releasably engage the rim engaging portion of the access strip when such access strip has been released from the cup rim and folded back.
U.S. Pat. No. 3,994,411 to Elfelt et al. teaches yet another disposable cup lid which includes a drinking flap or access strip. When such drinking flap is pivoted back from the cup rim to allow access to the contents of the cup, Elfelt uses a pull tab extending from the flap which may be laced through the straw slits in the central portion of the cup lid to retain the flap in open position.
U.S. Pat. No. 4,629,088 to Durgin teaches still another disposable container lid with a drink through opening. In order to retain the drinking flap in open position, Durgin employs a recess formed in the lid surface which has protruding therein a plurality of detents for engaging the drinking flap when it is pivoted down into such recess.
There is taught in U.S. Pat. No. 4,473,167 to Bailey still another disposable container lid which includes an access strip. With this strip, Bailey teaches a molded-in depression in which the access strip can be retained when it is pivoted back from the cup lid into such depression.
In U.S. Pat. Nos. 4,738,373 and 4,202,459, DeParales teaches disposable container lids with access flaps. Each lid taught in such references includes an arcuate recess adapted to compressively receive and retain therein the rim engaging portion of the access flap thereby holding such flap in open position.
From the foregoing, it can be seen that the prior art has relied predominately on molded in depressions or protrusions in the cup lid to retain the access flap in an open and non-interfering position. The principal exception to this is the above-referenced patent Elfelt which relies on a planar extending pull tab which must be laced through the straw slits in the cup lid to retain the access flap in open position. Nothing in the prior art teaches means for retaining the access flap in open position without adding more polymeric material to the lid to form such planar pull tabs, molded-in protrusions and molded-in depressions.